A mobile wireless terminal such as a smart phone or a tablet computer transmits and receives a radio wave to and from a radio base station provided by a communication operator, and performs wireless communication. When the mobile wireless terminal moves in an area where a plurality of radio base stations is installed, the mobile wireless terminal compares strength values of received powers (received radio waves) received from the respective radio base stations, and selects an optimum radio base station as a communication target. In general, a radio base station corresponding to the received radio wave having the highest strength is selected. An operation of switching the radio base station as the communication target from one radio base station to another radio base station is called handover.
Many documents related to the handover are presented. PTL 1 discloses a communication system in which a base station apparatus and a mobile station apparatus communicate with each other by a multiple access method of dividing a service area into a plurality of cells and allocating a radio channel to every communication and a base station apparatus used in the communication system. The base station apparatus includes cell determination means for determining a cell as a handover destination of the mobile station apparatus based on operation information including information indicating a movement direction of a moving object which moves in a predetermined route together with the mobile station apparatus in the predetermined route, positional information of the mobile station apparatus, and received strength of wireless communication between the mobile station apparatus and the base station apparatus.
In the disclosure of PTL 1, handover is conducted under a condition in which a moving object that moves on a railway of a tram arrives within a prescribed section within a prescribed route and the received power is equal to or less than a prescribed value.
As in the technology of PTL 1, a wireless communication system in which communication is performed in multiple modes by combining a plurality of modification schemes or a plurality of error correction coding schemes is suitable to realize high throughput and communication covering a wide area. In such a wireless communication system, since a physical transmission bandwidth is changed depending on the received power, it is reasonable to estimate and compare an upper limit throughput of a wireless communication area based on the strength of the received power from the radio base station.